As commonly understood, skin or other tissue grafting processes commonly involve the transplanting of a section of tissue to an injury of other anatomical abnormality associated with damage to or a loss of tissue. Some grafting processes involve the transplantation of a section of tissue from one area of a patient to another area of a patient. Other grafting processes; such, as allogeneic grafts (where donors and recipients are the same species), xenogeneic grafts (where donors and recipients are different species, such as porcine grafts), and prosthetic grafts (which include synthetic graft materials); can commonly be effectuated by cutting a graft from a sheet of graft material and subsequently applying the cut graft to the intended graft location. Various considerations must be addressed when forming grafts in such a manner.
One consideration to graft preparation relates to providing a sanitary condition associated with the entire process of forming each discrete tissue graft. Failure to properly attend to the sanitation of the process can result in contamination between the various devices associated with the cutting process, the blank materials, as well as already cut graft materials. Still further, inadequate attention to sanitary conditions can result in cross-contamination between already cut grafts, subsequent blank materials, and even subsequent material lots. Accordingly, devices associated with such tissue cutting processes must commonly be disposable and/or constructed to withstand periodic exposure to a suitable sanitation process to mitigate contamination between respective grafts.
Whether provided in a disposable or reusable configuration, another consideration that must be addressed during die formation is the suitability of the materials associated with forming or defining the die as being suitable for exposure to materials or tissues which are ultimately intended to be associated with and supported by a host body. That is, the die assembly and generation of the grafts preferably does not transfer materials that are ill-suited and/or dangerous for biological applications to the grafts.
Another consideration of the press cut generation of tissue grafts relates to providing a graft product that can satisfy generally uniform or repeatable size parameters. In order to press cut graft materials, a cutting edge defined by a press die must be maintained in a generally planar arrangement such, that the cutting edge can pass through the graft material in a substantially orthogonal direction relative to the exposed surface plane of the material to generate grafts that are of substantially the same size and which maintain a robust graft edge for subsequent cooperation adjacent tissue of an underlying patient. Movement of the cutting edge relative to an underlying blade support or deviation of the blade during die formation and/or sterilization process can result in a die configuration that is susceptible to incomplete cut operations or undesirable cut profiles. Such shortcomings can detract from a repeatable generation of a uniform graft product and/or decrease the efficiency with which grafts can be created.
Still further considerations associated with graft production relate to improving the acceptance or integration of the graft during healing. Commonly, graft tissue blanks are prepared, during or immediately prior to use, by meshing, also called fenestration. During fenestration, small perforations, slits, or cuts are formed in the donor tissue. These fenestrations allow the donor graft to be stretched thereby increasing the surface area of the donor graft and reducing the amount of graft material needed to reconstruct damaged dermis. In autograft processes, such considerations reduces the trauma and scarring associated with the donor area and allows the donor area to heal more quickly than it would if more graft tissue were harvested.
Fenestration of graft material also improves healing of the wound area. The perforations, and openings associated therewith due to stretching of the donor graft material, increases the amount of graft perimeter available for capillary pass-through and connection with other vessels. The openings associated with the fenestrations also allows fluids produced by the wound during healing to drain thereby mitigating capture of the fluid which may lead to infection between the graft and the wound.
Donor graft material is commonly fenestrated manually through the use of either a scalpel or by passing the donor graft tissue through a mechanical mesher. Such approaches have various drawbacks. Manually meshing the graft tissue with a scalpel can be tedious and requires the time and skill of highly qualified technicians. Even with the most skilled technicians, such processing often produces a less than uniform fenestration pattern which can result in undesired tearing and/or non-uniform presentation of the openings associated with the fenestrations when the graft tissue is stretched during use. Although mechanical meshers tend to mitigate some of the concerns associated with uniform fenestration production, use of such machines present their own complications associated with production of the desired fenestrated graft tissue.
Mechanical meshes commonly rely on using opposing rollers that flatten and perforate the graft tissue as it is passed therethrough. Such treatment of the donor graft tissue is unduly aggressive and can result in blemishes such as pock marks or the like in healed tissue. Such blemishes, depending on the severity and patient location, commonly require additional cosmetic surgery to resolve. Still further, donor graft tissue can commonly become torn or entangled when passed through such mechanical meshes. The severity of the damage to the tissue can render the graft tissue unusable for its intended purpose and effectively wasting the same. Such considerations are particularly problematic during autograft processes. Still further, during mechanical meshing, small particles of biological material may separate from the graft and remain adhered to the mesher thereby complicating the ability to maintain the desired level of sanitation associated with the same. Still further, both manual fenestration and utilization of mechanical meshers require clean room levels of sterilization yet further increasing costs associated with production of the same.
Accordingly, it would be desirable to have an assembly and method for generating fenestrated graft tissue blanks in a more uniform, sanitary, and conveniently implemental manner. The present invention discloses a press cut die assembly and method of forming a die assembly for generating fenestrated graft tissue blanks.